The present invention is directed to the art of hydraulic master cylinder devices of the type adapted for manual actuation and, more particularly, to hydraulic hand brake apparatus. The present invention is particularly well suited for use in motorcycle hand brake and hydraulic clutch operations and will be described with particular reference thereto. However, it is to be appreciated that the present invention can be applied in a wide range of applications such as in the bicycle arts, motorized vehicle arts, or anywhere pressurized fluids are used to control one or more devices such as brakes, clutches or the like. Accordingly, the invention is not limited to the preferred embodiments described in detail below.
Drawings showing examples of prior art hydraulic master cylinders for use with motorcycles are shown in FIGS. 1-3. Generally, the hydraulic master cylinders have an integral piston adapted to be actuated by a lever provided adjacent to a handle grip which is positioned in a spaced apart relationship relative to motorcycle handlebars. FIG. 1 shows an end view of a master cylinder 1 mounted on the handlebar 2 using a bracket 3. FIG. 2 shows a master cylinder 1 positioned alongside of the handlebar 2 and a handle switching unit 4 mounted on the handlebar 2 coaxially therewith. A hydraulic line 5 extends from the master cylinder 1 in a spaced apart relationship relative to the handlebar 2 substantially as shown.
One disadvantage with typical prior art master cylinder devices is that they are constructed in a manner to provide little or no protection to the hydraulic fluid lines extending between the master cylinder and the actuation device. More particularly, as best illustrated in FIG. 2, the brake line 5 extends from the master cylinder 1 generally alongside the handlebar 2 in a substantially unprotected and rather vulnerable position. More particularly, as those skilled in the motorcycle or bicycle arts can appreciate, brake lines such as hydraulic fluid lines or cables often snag on clothing or other articles causing a potentially dangerous situation. Further, the generally unprotected nature of the brake lines 5 renders them vulnerable to severe mechanical damage, such as rupture, kinking, or the like, when they are exposed to excessive force or impact. This poses a particular problem in connection with high performance motorcycles and with motorcycles built for racing.
In addition to the above, another concern with prior art master cylinder and brake line arrangements is primarily aesthetic in nature. More particularly, external brake lines are not visually appealing. On some motorcycles, the brake lines are chrome plated or wire braided to provide a pleasant appearance. Even so, the external brake line routing detracts from the overall visual impact of the motorcycle. This is particularly true in custom motorcycles where external brake lines detract from the appearance of highly detailed frames, engines and other parts.
Another disadvantage with prior art motorcycle hydraulic master cylinder apparatus will be described below in connection with reference to FIG. 3. As shown there, a handlebar 6 defines a major central longitudinal axis 6. During use of the device shown in FIG. 3, a motorcycle operator places his palm onto the handlebar portion 6 and extends the forefingers around a trigger member 8. By squeezing on the trigger portion 8, rotation is established in the direction labeled by the arrow 9 in the Figure. An actuation foot member 10 moves together with the grip portion 8 substantially along a line 11 parallel to the major central axis 7 of the handlebar portion 6. In the configuration shown in FIG. 3, a piston (not shown) contained within the hydraulic master cylinder is linearly slidable along the line 11 substantially parallel but offset from the major access axis 7 of the handlebar portion.
One disadvantage with the system shown in FIG. 3 is that the piston within the master cylinder is slidable along an axis offset from the major axis of the handlebar portion. Accordingly, the overall hydraulic master cylinder system is generally bulky and therefore has a reduced aesthetic appeal. In addition to unnecessarily consuming space, the relative offset between the axis 11 defined by piston actuation and the hand grip portion 7 results in a mechanical disadvantage to the motorcycle rider.
In accordance with the above, therefore, it is desirable to provide an integrated handlebar and master cylinder having a piston and hydraulic line coaxially aligned with the central axis of the handlebar. Preferably, the piston is slidable along an axis coaxial and coincident with the major central axis of the hand grip portion of the motorcycle handlebar.
It would further be desirable to provide an integrated handlebar and master cylinder apparatus adapted for attachment to an associated handlebar, the master cylinder having a piston movable along an axis coaxial with an axis defined by the handlebar portion. Preferably, the axis defined by the handlebar portion together with the axis defined by the piston within the master cylinder is coaxial and coincident with the axis defined by the associated handlebar.
It would be desirable to provide a system such as described above so that a mechanical advantage is realized during manual actuation of the subject system.
Further, it would be desirable to provide a system such as described above to enable the routing of hydraulic brake lines or the like directly from the master cylinder and through at least the handlebar and top triple tree portions of a motorcycle. This simultaneously protects the brake lines from damage and is aesthetically pleasing.
The subject invention provides an integrated handlebar and master cylinder apparatus having a slidable piston and a hydraulic line both of which being coaxially aligned with the major central axis of a hand grip portion of the handlebar. The position of the piston within the subject system enables the piston to be linearly slidably directly along and coincident with the major central axis of the handlebar.
In addition, the subject invention provides an integrated handlebar and master cylinder device that includes a hydraulic line extending from the master cylinder substantially along an axis coaxial with and coincident with the major central axis of the handlebar. In that way, the hydraulic line is adapted for direct routing within the central cavity of the handlebar and motorcycle fork assemblies. This simultaneously provides protection to the hydraulic lines together with an improved aesthetic appearance.